Internal combustion engine



May 1, 1962 J. KRUGER INTERNAL COMBUSTION ENGINE Filed March 22, 1960 mums- 10 ZOrrwDmEOu OF INVENTOR J'OHANNES KRUGER ATTO R N EY United States Patent Ofilice 3,032,023 Patented May 1, 1962 p 3,032,023 INTERNAL COMBUSTION ENGINE Johannes Kruger, 56 Lovat Road, Durban (North), Natal, Union of South Africa Filed Mar. 22, 1960, Ser. No. 16,858 21 Claims. (Cl. 123-122) This invention relates to internal combustion engines and particularly to those of automobiles and the like.

The objects of the invention include the provision of fuel air mixture apparatus within the fuel tank of an engine system. Further, the invention contemplates preheating of the air-fuel mixture prior to cumbustion to improve the thermal efficiency and consequently the fuel economy and engine efiiciency.

In a specific embodiment of the invention, the heat of the engine exhaust gases is utilized to preheat the airfuel mixture. The heat exchange between exhaust gases and the mixture is effected within the muffler. Special provision is made for supplying the air-fuel mixture to the engine intake manifold when the engine is idling to avoid transfer of heat from the mixture on cold start, while admitting of heat transfer from the exhaust gases to the air-fuel mixture on warm idling. This is accomplished according to a further feature of the invention by locating the idling air-fuel mixture to the outside of, but in close proximity to the muffler. On the other hand, the main air-fuel mixture is passed through the mufiler in closer proximity to the exhaust gases, and heat transfer is optimized by provision of a heat exchange coil of one or more convolutions within the muffler.

For a better understanding of the invention, reference is made to the following detailed specification and the accompanying drawing, in which the single FIGURE is a schematic illustration, partly in perspective and partly in section, of a preferred embodiment of the invention.

The fuel tank 1 of the engine system is divided into a plurality of compartments by transversely extending porous felt pads or plates 30, which absorb the fuel and soak a further top cover felt plate 31, atop which the mixture vaporization unit 32 is situated. Tank 1 is equipped with the usual filler neck 33, whereas unit 32 receives intake air through an inlet 34 of its left endwall. Air is admitted from the atmosphere through a filter unit 2 and a communicating pipe, which terminates in opening 34. The fuel tank 1 is the liquid fuel supply for the engine system and is also the main fuel air mixing means for the engine system. This latter function is basically carried out via the air flow through the tank 1. The plates 30 and 31 are utilized not only as an aid to this function in that they provide both absorbent elements and a decompartmentalized fuel tank 1 in which the upper compartment 32 acts as an independent mixing chamber, but also, the plates act to restrain fuel splash into the vaporization unit 32 in moving vehicles in which the engine system may be used. In this respect, the plates 30, 31 need not be made of a porous material at all and may be variously spaced both or either within the fuel compartment and between the fuel compartment and the vaporization unit 32.

Unit 32 is divided into two end compartments by means of transversely extending interior walls 36 and 37, and four central compartments by means of three longitudinally extending interior walls, designated collectively 38, which terminate at interior walls 36 and 37. The interior walls are provided with openings located-to cause passage of the vapors along the path through the several compartments as identified by the indicated arrows, whereby fuel vapor is absorbed into the mixture from the felt plate 31. The flow into the final, rightmost compartment is controlled by means of a valve 35, which is actuated by a pressure diaphram acting against a compression bias spring 39 to position rod 40 coupled to valve 35. The connecting rod is formed in two parts which are joined together by means of an adjustable turnbuckle 41. A second valve 43 is also coupled to connecting rod 40 to the right of the turnbuckle, and serves to control air flow to the final compartment through an opening 44 in the right endwall. The turnbuckle may be adjusted to the position for optimum fuel mixture and air flow. The diaphram 10 is actuated by pressure of exhaust gases derived via a pipe 45 which communicates with the main exhaust pipe 46.

A main or power intake manifold line 6 and an idling intake manifold line 7 communicate with the final com partment of the unit 32, the latter penetrating into the interior of the same and being provided with suitable perforation 47. The intake line 6 extends into the interior of the muffler 47 in which it is doubled back or convoluted to the form of a coil. This shape permits optimum preheating of the mixture due to the heat transfer from the exhaust gases which enter the mufller 47 via pipe 48 and emerge therefrom via exhaust pipe 46. It should be understood that the number of convolutions of pipe 6 within the mufiler 47 may be increased as desired, the illustrated arrangement being merely dia-- grammatic.

Line 6 terminates in the main intake manifold 23, the mixture passing through normally open safety valve 22 and normally open gas throttle valve 21 via the indicated path to the engine combustion chamber. Valve 21 is operated by means of the usual throttle lever (not shown). Valve 22 is supported by means of a bearing member 49 including bearing sleeve 50, on which a compression spring 51 is seated. The latter normally urges the valve 22 leftward to permit passage of the mixture. The valve is closed in the event of backfiring from the combustion chamber by pressure of the gasses which overcome the bias of spring 51 as a protective measure.

The idling intake manifold line 7 extends generally in parallel relation to line 6, but remains outside of, although in close proximity to the rnulfier 47 for the reason previously stated. This arrangement provides the desired rich mixture for starting and idling. Line 7 is somewhat enlarged to form line 11 prior to communication with the combustion chamber. Line 11 terminates in a normally open spring safety ball valve 12, which is functionally similar to safety valve 22 and is also provided as a safety device in the case of backfiring. After passing through the valve 12, the idling mixture enters the intake manifold 23 via a longitudinal port 52 and a transverse port 53. An adjustable screw 13 is provided in alignment with port 53 to control the mixture flow from port 52 to port 53. The mixture is also controlled by means of a needle valve 15 which opens and closes to variably extend an air blade opening 14 which communicates with the port 52. The needle 15 is disposed slidably within port 52 and is actuated by means of a diaphram 16 that is biased by means of a compression spring 17. The diaphram is actuated by suction pressure which is supplied via a line 19 that communicates with the diaphram chamber 54. Pressure is derived via line 19 by virtue of its termination within the manifold 23 near its outlet 55 to the combustion chamber. Diaphram 16 is provided with an adjustable stop screw 18 against which spring 17 urges. This permits adjustment of the spring pressure for further control of the idling mixture.

A still further safety valve 20 normally closes a safety opening of the manifold 23 which is located opposite the opening 55. The safety valve 20 is of a structure similar to that of the safety valve 22 and is provided for the same purpose, namely as a safeguard against backfiring from the combustion chamber. The valve 20 opens increases again and rapidly so.

in the case of backfiring and thus diverts backfire gas pressures from the fuel tank.

The described apparatus operates largely in conventional manner and therefore'an extensive description of the operation is deemed unnecessary. However, the following features are noteworthy. When starting'the engine, the gas throttle valve 21 is closed. Air passes through the air filter 2, then strikes over the fuel absorbing plate 31. The fuel-air mixture then passes through lines 7 and 11 and safety valve 12 to the corresponding cylinder. At this time the mixture idling needle 15 is in the closed position. This provides a rich mixture for easy starting.

As the engine starts, suction builds up and diaphram 16 pulls needle 15 against its accelerating spring 17 to the adjustable screw 18. This opens the air bleed 14 to provide the proper mixture for idling. Operation of the diaphram 16, and consequently of the needle 15, depends upon the buildup of the manifold vacuum and the consequent pressure differential. In the idling condition, the main mixture valve 44 is slightly opened.

When the gas throttle valve 21 is suddenly opened, the manifold vacuum decreases and thereby releases the spring 17 which holds the idling mixture needle 15 in position. As a result, the air bleed 15 closes, and momentarily a rich mixture is provided for smooth acceleration. However, as soon as the engine runs up, the manifold vacuum As a result, the idling mixture needle 15 is pulled back to its normal operating position. As a consequence of the opening of the main throttle valve 21, manifold suction also opens the previously closed safety valve 22. As soon as the engine runs up, pressure increases in the exhaust lines 4 8, 46 and 45. This pressure regulates the diaphragm which operates the main mixture valves 35 and 43. The exhaust gases transfer heat to the mixture within the muffler 47, thereby highly improving engine efiiciency and fuel economy. The selection, within mufiler 47, for the location of such heat exchange enhances these desirable results.

Thus it will be seen that in accordance with the invention, there has been provided a particularly useful and advantageous arrangement of a fuel vaporizer for an internal combustion engine. A presently preferred embodiment of the invention has been described, but this should be considered as illustrative of the invention and not as a limitation thereof. Further modifications may occur to those skilled in the art, and it is intended that they be embraced Within the scope of the invention as limited only by the appended claims.

What is claimed is:

1. In an internal combustion system, a liquid fuel supply tank, fuel air mixing means in said tank including air intake means communicating with said tank above the fuel level thereof, intake manifold means, fuel-air mixture conducting means interconnecting said intake manifold means and said tank above the fuel level thereof, and engine exhaust discharge means arranged in heat exchange relationship with said fuel-air mixture conducting means.

2. In an internal combustion engine having fuel air mixing means, intake manifold means receiving-the fuelair mixture from the fuel air mixing means, and engine exhaust discharge means including a mufiier, the improvement comprising fuel-air mixture conducting means interconnecting said fuel air mixing means and intake manifold means and passing through said mufiier in heat exchange relationship With the engine exhaust gases for preheating the fuel-air mixture prior to introduction to said manifold means.

3. In an internal combustion engine having fuel air mixing means, intake manifold means receiving the fuelair mixture from the fuel air mixing means, and engine exhaust discharge means including a muflier, the improvement comprising a fuel-air conducting pipe interconnecting said fuel-air mixing means and intake manifold means and passing through said muffler and having a convoluted portion therein for receiving heat from the engine exhaust gases to preheat the fuel-air mixture prior to introduction to said manifold means.

4. In an internal combustion engine having fuel air mixing means, intake manifold means receiving the fuelair mixture from the fuel air mixing means, and engine exhaust discharge means including a muffler, the improvement comprising an idling fuel-air mixture conducting pipe interconnecting said fuel air mixing means and manifold intake means and passing to the outside of and in close proximity to said mufller, and a main fuel-air mixture conducting pipe also interconnecting said fuel air mixing means and manifold intake means and passing through said muffler in heat exchange relationship With the engine exhaust gases for preheating the main fuel-air mixture prior to introduction to said manifold means.

5. In an internal combustion engine having fuel air mixing means, intake manifold means receiving the fuel-air mixture from the fuel air .mixing means, and engine exhaust discharge means including a muffler, the improve ment comprising an idling fuel-air vmixture conducting pipe interconnecting said fuel air mixing means and manifold intake means and passing to the outside of and in close proximity to said muffler, and a main fuel-air mixture conducting pipe also interconnecting said fuel air mixing means and manifold intake means and passing through said mufiier and having a convoluted portion therein for receiving heat from the engine exhaust gases to preheat the main fuel-air mixture prior to introduction to said manifold means.

6. In an internal combustion engine, fuel air mixing means, engine manifold intake means having a main fuelair mixture channel, an idling fuel-air mixture channel providing an air bleed, and a channel common to the aforesaid two channels, the common channel being for delivery of the fuel-air mixture to the combustion chamber, engine exhaust discharge means including a muffler, an idling fuel-air mixture conducting pipe interconnecting said fuel air mixing means and said idling channel and passing to the outside of and in close proximity to .said muffier, a main fuel-air mixture pipe interconnecting said fuel air mixture means and said main fuel-air mixture channel and passing through said muffler, a needle valve movably disposed in said idling channel for controlling said air bleed, diaphragm means responsive to suction in said common channel for actuating said needle valve, and a gas throttle valve located at the junction of said main fuel-air mixture channel and said common channel.

7. The invention as set forth in claim 6 provided with a safety valve in the main fuel-air mixture channel, said safety valve being closable' responsive to back firing from the combustion chamber to protect the fuel air mixing means.

8. The invention as set forth in claim 6 provided with a safety valve in the idling fuel-air mixture channel, said safety valve being closable responsive to back firing from the combustion chamber to protect the fuel air mixing means.

9. The invention as set forth in claim 6 provided with a safety valve in the common fuel-air mixture channel, said safety valve being openable responsive to back firing from the combustion chamber to divert back firing gases from the main and idling fuel-air mixture channels.

10. The invention as set forth in claim 6 provided with a safety valve in each of said aforesaid channels, that in the common channel being openable responsive to back firing from the combustion chamber to divert back firing gases from the main and idling fuel-air mixture channels, and those in the remaining two channels being closeable responsive to such back firing to protect the aforesaid fuel air mixing means.

11. The invention as set forth in claim 6 wherein the main fuel-air mixture interconnecting pipe has a convoluted portion within the muflier for optimising heat reception from the exhaust gases.

12. The invention as set forth in claim 6 wherein the main fuel-air mixture interconnecting pipe has a convoluted portion within the muffier for optimising heat reception from the exhaust gases and is further provided with a safety valve in the idling fuel-air mixture channel, said safety valve being closable responsive to back firing from the combustion chamber to protect the fuel air mixing means.

13. The invention as set forth in claim 6 wherein the main fuel-air mixture interconnecting pipe has a convoluted portion within the muffler for optimising heat reception from the exhaust gases and is further provided with a safety valve in the idling fuel-air mixture channel, said safety valve being closable responsive to back firing from the combustion chamber to protect the fuel air mixing means.

14. The invention as set forth in claim 6 wherein the main fuel-air mixture interconnecting pipe has a convoluted portion within the muffler for optimising heat reception from the exhaust gases and is further provided with a safety valve in the common fuel-air mixture channel, said safety valve being openable responsive to back firing from the combustion chamber to divert back firing gases from the main and idling fuel-air mixture channels.

15. The invention set forth in claim 6 wherein the main fuel-air mixture interconnecting pipe has a convoluted portion within the muffler for optimizing heat reception from the exhaust gases and is further provided with a safety valve in each of the aforesaid channels, that in the common channel being openable responsive to back firing from the combustion chamber to divert back firing gases from the main and idling fuel-air mixture channels and those in the remaining two channels being closable responsive to such back firing to protect the aforesaid fuel air mixing means.

16. In an internal combustion engine system, a liquid fuel supply tank, a liquid fuel reservoir in the lower portion of said tank, liquid fuel intake means adjacent said lower portion, a fuel air mixing chamber in the upper portion of said tank, air intake means adjacent said upper portion, intake manifold means, fuel-air mixture conducting means interconnecting said intake manifold means and said fuel air mixing means in the upper portion of said tank.

17. In the internal combustion engine system of claim 16 wherein plate means are interposed between said liquid fuel reservoir and said fuel air mixing chamber, said plate means being arranged relative to said reservoir and said chamber for permitting vapor exchange from said reservoir to said chamber.

18. In the internal combustion engine system of claim 17 wherein said plate means extend within said liquid fuel reservoir and are made of a porous material.

19. In the internal combustion engine system of claim 17 wherein wall means form at least two compartments in said fuel air mixing chamber and said fuel-air mixture conducting means communicates with one said compartment and said air intake means communicates with the other said compartment, valve means are interposed between said compartments, and control means adjacent said tank are provided for opening and closing said valve.

20. In the internal combustion engine system of claim 19 wherein there is provided engine exhaust discharge means, and said control means comprises pressure sensitive means interconnecting said engine exhaust discharge means and said valve means, said valve means and said pressure sensitive means being arranged for actuation of the former by the latter.

21. In the internal combustion engine system of claim 20 wherein there is provided a second valve means adjacent said other compartment and communicating with the air on the outside of said fuel air mixing chamber and said control means interconnects said second valve and engine exhaust discharge means.

References Cited in the file of this patent UNITED STATES PATENTS 827,643 Lawrence July 31, 1906 1,406,598 Wilson Feb. 14, 1922 1,686,180 Shiffer Oct. 2, 1928 2,683,029 Ricardo July 6, 1954 

